This invention relates generally to improvements in manufacturing processes for making thrust chambers of the type used in jet or rocket engines. More particularly, this invention relates to an improved and relatively economical yet precision production method for making thrust chambers of the type having a channeled wall defining a converging-diverging thrust chamber.
Thrust chambers for jet and rocket engines are well known in the art for use in the combustion of fuels with an oxidizer and for discharging combustion products from the engine in a manner generating substantial thrust. Such thrust chambers define a converging-diverging geometry through which the combustion products are generated and flow to provide the desired forward reaction force or thrust. In many current thrust chamber designs, a channeled wall configuration is used wherein relatively small fluid flow channels are formed circumferentially about the thrust chamber for passage of an engine process fluid in heat exchange relation with combustion products. Such channeled wall configurations are used when heating of the process fluid and/or cooling of the thrust nozzle structure is desired for achieving higher engine performance levels and/or extended service life of the thrust chamber/nozzle structure.
While channeled wall thrust nozzles offer significant advantages in engine operation, the channeled wall structure is relatively difficult and costly to manufacture particularly in combination with the converging-diverging geometry of the thrust chamber. Moreover, in some engine applications, the array of fluid flow channels must have a substantially uniform size and shape within close tolerance limits for proper heat exchange operation. To meet these design criteria, such channeled wall thrust nozzles have in the past been produced from a forged thrust chamber liner of the desired converging-diverging shape, wherein this liner is appropriately machined to form longitudinally extending external channels of uniform size and shape which follow the converging-diverging contour. These machined channels are then enclosed by an outer wraparound housing shell. However, the requirement for precision channel machining on each thrust nozzle significantly increases the time and cost of production.
There exists, therefore, a need for improvements in production methods for manufacturing channeled wall thrust nozzles, wherein process fluid flow channels are formed with relatively high precision while avoiding costly and complex machining steps. The present invention fulfills these needs and provides further related advantages.